1. Field of the Invention
The present invention relates to a simplified bookbinding device for binding a plurality of sheets using a twin-ring.
2. Description of the Related Art
Various bookbinding techniques are used for binding a plurality of sheets to one book. Among the bookbinding techniques which are well known are thread binding using a machine, threadless binding by gumming the back with an adhesive, wire-stitch binding with staples of a stapler, spiral binding with a spiral coil, and twin-ring binding (double-ring binding) with a wire called a twin-ring, a double-ring, or a double-loop ring.
There are various types of bookbinding techniques, as described above. However, when the bound book is opened at 360 degrees, the thread binding, the threadless binding, and the wire-stitch binding are not employed, but the spiral binding or the twin-ring binding are mainly adopted. However, the spiral binding has such a drawback that the left and right pages have slight vertical displacement when opened at 360 degrees as well as advantages that it is cheap and superior in durability because a metallic wire is used. When such vertical displacement is not desired, the twin-ring binding is employed. Although the twin-ring used as a binding device for the twin-ring binding is in general more delicate and expensive than the spiral ring, it has also an advantage of being suitable for storing long-term-use documents because of its unique configuration in which two wires are inserted through one hole. Therefore, the demand for the twin-ring binding is greatly improved.
Typically, the twin-ring is formed in such a way that an iron wire coated with nylon is formed in a unique C-shape in section with a twin-ring forming machine and is wound around a bobbin. At the time of bookbinding, the bobbin, around which the twin-ring is wound, is attached to a twin-ring binding device, and a twin-ring of necessary length is pulled out for use.
Referring now to FIGS. 13A to 13C and 14, a conventional twin-ring binding will be specifically described. FIGS. 13A is a perspective view of a twin-ring 1 before binding operation; FIG. 13B is a sectional view of the twin-ring 1, taken on line bxe2x80x94b; and FIG. 13C is a sectional view of the twin-ring 1 after the section has been pressurized into a substantial O shape. FIG. 14 is a perspective view of the twin-ring 1 after the binding operation.
As shown in FIG. 13A, the twin-ring 1 is formed by alternately connecting a large number of U-shaped or V-shaped binding pieces 2 and connecting pieces 3, which are made of one wire. As shown in FIG. 14, the binding pieces 2 are each inserted through holes 8 punched in the side of sheets 9 and the connecting pieces 3 connect between the holes 8 in the sheets 9. Before binding, the twin-ring 1 has a substantially C shape in section in which two semicircular-arch-shaped parts are connected at a bend portion 5, as shown in FIG. 13B. At that time, the binding pieces 2 are opened (gap) with respect to ends 4, thus allowing the insertion of the sheets 9. At the time of binding, the twin-ring 1 is pressurized by a predetermined force F to bring the end of each binding piece 2 and the end 4 into close to each other into a ring shape at the bend portion 5 (refer to FIG. 14). The twin-ring 1, at this time, is deformed (bent) such that the two semicircular-arch-shaped parts form one circle in section, as shown in FIG. 13C.
The wire for the twin-ring 1 is selected depending on the thickness of the sheets 9 to be bound (refer to FIG. 14). Although the wire is as small as about 1 mm in diameter, it requires a substantial pressure to deform, in section, the two wires inserted through the holes 8 in the sheets 9 from the shape shown in FIG. 13B to the shape shown in FIG. 13C. Therefore, conventionally, for twin-ring binding, relatively large exclusive-use twin-ring binding devices are used which incorporate a punching operation for punching a plurality of holes in the side of the sheets. However, since such binding devices occupy too much space for installation, it is difficult for individuals to perform bookbinding with ease, thus growing a demand for a simplified binding device for easily performing twin-ring binding.
In view of the state of the art set forth above, it is an object of the present invention to provide a simplified bookbinding device for a twin-ring, which provides a binding mechanism separate from a punching operation, downsizes the device for decreasing the space for installation, and simplifies the operation, thereby allowing individuals to easily perform bookbinding using the twin-ring.
In order to achieve the above object, according to a first aspect of the present invention, there is provided a bookbinding device used when stacking a plurality of sheets each having a plurality of holes punched in advance, and binding the plurality of sheets together by inserting a twin-ring through each of the holes and deforming the twin-ring by pressure, comprising an anvil; a press section for pressurizing the twin-ring between it and the anvil; a power transmission section for sliding the press section; and an operating section for sliding the power transmission section, wherein the power transmission section is moved along the length of the twin-ring; and the press section is moved in a direction perpendicular to the length of the twin-ring.
With such a configuration, the bookbinding device can be formed small in its entirety, which is long in length along the length of the twin-ring and is short in length perpendicular to the length of the twin-ring, thus saving space for installation.
According to the first aspect of the present invention, the bookbinding device further comprises an adjusting section for determining in steps the sliding start position of the power transmission section.
With such a configuration, when twin-rings of various diameters are deformed by pressure, a suitable compression amount can be determined in steps so as to prevent excess compression in each case.
According to the first aspect of the present invention, the bookbinding device further comprises a retaining section for retaining the twin-ring to the substantially full length of the side of the main body.
With such a configuration, the twin-ring can quickly be inserted through the holes in the sheets by retaining the twin-ring over the substantially full length.
While the simplified bookbinding device according to the present invention is principally configured as described above, when the motion of the operating section is converted to a sliding motion of the power transmission section, the power transmission mechanism is not limited to a rack and pinion, but a link mechanism, a cam mechanism, or other gear mechanisms may be used for transmitting power to the operating section. Also, the rotating direction of the operating section is not limited to the direction along the length of the twin-ring, but may operate the binding mechanism by a small force from another direction.